Molded article



lNav. 3, 1942,. .Q -B. RYPlNsKl v I 2,300,974

Y uoLnEn ARTICLE Filed April 6, `1940 INVFNTOR ALBERT B. RYPINSKIATTORNEY o Patented Nov. 3, 1942 MOLDED ARTICLE Albert B. Rypinsk-,Laurelton, N. Y., assignor to Metropolitan Device Corporation, Brooklyn,N. Y., a corporation of New York Application April 6, 1940, Serial No.328,273

7 Claims. (C1. 200k-168) The invention herein disclosed relates to anarticle constructed'from molded material and including elements fastenedthereto, such for example as the case, base or support of an electricalde-vice.

UIn -certain articles, particularly electrical devices, it is expedientto mold or stamp certain parts such as supports, bases, cases, and othernon-conducting partsffrom electrical insulating material such, forexample, as Bakelite. Specific examples of this kind are switches andcircuit breakers of the smaller sizes, the cases for which may be moldedfrom moldable electrical insulating material. These cases have variousparts secured thereon such as stationary contacts, conductor strips andterminals. Such parts must be Very secure so that strong pressure onterminalswill not cause displacement of the parts.

.- `It is one of the primary objects of this invention to securerelatively thin strip material, terminals or plates into a relativelythin wall of molded material. This maybe done after the wall is molded.Another ob-ject is to accomplish the securing of .thin plates in thinwalls Without the necessity for lateral punches in the moldingoperation.

Articles of this kind are commonly molded in a two part mold, the partsof which are separable in a direction perpendicular to the plane ofseparation. Where an article has openings, grooves, etc., that require-punches or cores which extend perpendicular to the direction ofseparation of the mold parts, special, expensive equipment is required,the molding operation is slower and the yarticle is correspondingly moreexpensive. It is common lpractice in design of parts for molding to havea punch from the top of the mold meet a punch from the bottom of themold, the two intersecting in a common plane but displaced one from theother, to form a lateral opening. This method is utilized herein toprepare a thin moldable wall to receive and retain parts secured theretoin accordance with the invention.

The walls of molded articles need to be relatively thin because thecuring time or time required for lthe material to form a homogenous massof adequate strength, varies with the thickness of the wall.

In accordance `with the invention a thin wall is molded with a slot fromthe top and with an intersecting but displaced slot in the same wallfrom the bottom. One loose member ie slid in tothe end of the slot fromthe top and a second loose mem-ber is installed against the end of theslot from the bottom. Then the members are secured together. Theboundaries of the slots prevent movement of the members with relation tothe wall, after they are secured together.

A circuit breaker embodying the invention is disclosed, by way ofexample, in the accompanying drawing and described in detail below. Inthe drawing:

Fig. 1 is a plan view with the cover partialli7 broken away;

Fig. 2 is an end elevation of the same; and

Fig. 3 is a transverse section taken on the line 3 3 of Fig. 1.

The circuit breaker illustrated in the drawing is of the kind disclosedin my copending applications, Serial Nos. 309,521 and 321,022, iiledDecember 16, 1939, and February 27, 1940, respectively. .These circuitbreakers primarily include a case and an operating unit consisting ofrotatable parts. The case constitutes an enclosure for .the operatingparts and a support for the stationary contacts which are positionedwithin the 'case for cooperation with contacts on one of the movableparts. These stationary contacts are mounted on contact strips that aresecured to the case in such relation that connections may be madethereto through terminal screws accessible on the outside of the case.The case is molded from Bakelite or some equally good electricalinsulating material and the contact `strips must be mounted thereon suchthat strong pressure on the terminal screws will not cause displacementof the contact strips.

fThe circuit breaker disclosed for the purpose of illustrating thisinvention is a single circuit breaker and includes a case 'I open at thebottom and molded in one piece from Bakelite or other Inoldableelectrical insulating material. This case has a compartment having anopening through the top. rIn the compartment there is mounted anoperating unit, the unit 2. This operating unit is inserted in thecompartment through the bottom of the case and a cover 3 is provided forthe case and en-closes the unit within the case, the cover beingprovided with an opening through which a linger piece t extends. Theringer piece is provided for the manual operationof the circuit breaker.

For the circuit breaker unit, there a pair of stationary contacts (notshown), one at each end of the compartment in which the unit is mounted.These contacts are connected to or mounted upon contact strips whichextend through openings in the case andthat .are secured to the case.fIhe contact strips are identical and mounted in the same Way. For thisreason lbut one of the contact strips and the mounting thereof on thecase will be described.

At the end of the section of the case in line with the compartment inwhich the unit 2 is mounted, there are provided two grooves, enteringfrom opposite edges of the end wall and having overlapping sectionsintermediate the opposite edges of the end wall. One of these grooves,5, enters from the top edge of the case; it is at the inner surface ofthe end wall 6, parallel to the plane of the wall and terminates at apoint I intermediate the edges of the wall. The other groove 8 which isof lesser width than the groove 5 enters from the opposite or lower edgeof the end wall; has a section 9 which overlaps the groove 5 andterminates at a point I0 intermediate the edges of the wall. The grooveslie in parallel planes and are so related that an opening is effectedthrough the wall at the overlapping sections of the grooves. Since theoverlapping section 9 of the groove 8 is of lesser width than the groove5, shoulders are formed on each side of the opening effected by thegrooves at the point of communication of the overlapping sections orintermediate the ends of the opening.

As will be observed from the drawing, the case I is rectangular. It ismolded in a die which separates along a plane transverse to the side andend walls and the parts of which separate by relative movement parallelto the grooves 5 and 8. All of the cavities of the case are thus made bycores or punches extending from the mold parts and parallel to the lineof movement along which separation of the mold parts is eiected. Thusthe compartment for the operating unit and the groove 8 are formed bycores or punches extending from the mold part which forms the bottom ofthe case. Similarly the groove 5 and the passage I I inwardly of thegroove 5 are formed by punches extending from the mold part that formsthe top of the case and parallel to the line of separation of the moldparts.

In the groove 5, there is placed a square nut I2y of a width, betweenflats, such that opposite edges engage the sides of the groove and theface engages the shoulders formed intermediate the ends of the openingeffected by the overlapping sections of the grooves 5 and 8. When thisnut is inserted in the groove, it is provided with a central, extruded,cylindrical extension I3 axially aligned with the tapped opening throughthe nut. The nut seats in the bottom of the groove 5 and the extensionI3 extends through the opening eected by the overlapping sections of thegrooves. The nut is thus engaged on three edges and part of one face.

Within the groove B the end section of a connector strip I4 is received.This connector strip carries on its inner end a contact (not shown) andextends along the bottom of the end wall and along the groove 8. The endportion of the connector strip is received in the section 9 of thegroove 8. An opening is provided through which the cylindrical extensionI3 passes when the conductor strip is placed in the groove. The end ofthe strip abuts against the upper edge of the groove 8.

When the nut and conductor are in the respec- 7 tive grooves as abovedescribed, the cylindrical extension is rolled over forming a flange orbead I5 by which the nut and conductor strip are rigidly securedtogether. The passage II provides space in which an anvil may be held totake up fil) all)

the strains incident to the rolling over 0f the eX- tension I3. Inaddition, it simplies the placing of the nut in place, and in thefinished case forms a vent through which gases resulting from arcs mayfreely pass out of the case. The nut I2 forms a tapped hole for theterminal screw I6 through which a conductor may be connected to thestrip I4.

The conductor strip I4 extends under the end wall of the case, a spaceI'I being provided for this purpose. These strips are covered andinsulated by the bottom I8 Which is secured to and closes the bottom ofthe case. The circuit breaker unit has an adjusting screw I9 with whichthe breaker is set for its rated capacity. Since the operating partsmust be assembled from the bottom of the case, once the terminal ttingshave been secured to their respective nuts, these parts are xed in thecase. Since they prevent the removal of the circuit breaker unit oncethey are in place, the securing means become one means for rendering theadjustment of the circuit breaker inacessible. The cover is permanentlysecured on the case by -rivets or screws 20 and 2| which extend throughthe cover, the case and the bottom strip I3.

From the foregoing description of the embodiment of the inventionillustrated in the drawing, it will be seen that by this invention thereis provided an arrangement by which parts may be rigidly secured in athin wall of a molded article without the necessity of utilizing lateralcores or punches in the forming of the article. In addition there is inthe specic circuit breaker disclosed an arrangement whereby the breaker,before the cover is assembled thereon, may be tested and adjusted andwhen the cover is in position the adjusting screw is inaccessible.

It will be obvious that various changes may be made by those skilled inthe art in the details of .the embodiment of the invention disclosed inthe drawing and described above within the principle and scope of theinvention as expressed in the appended claims.

I claim:

l. In a device of moldable material, the combination comprising a wallhaving an opening therethrough effected by overlapping sections ofgrooves lying in parallel planes entering from different points at theedge of the wall and of different width at the overlapping sections, anelement in one of the grooves having an opening therethrough, and aninternally threaded fastening element in the other of said grooveshaving an extension thereon passing through the opening in the rstmentioned element and securing the two elements together.

2. In a device of moldable material, the combination comprising a wallhaving an opening therethrough effected by overlapping sections ofgrooves lying in parallel planes entering from diierent points at theedge of the wall and of diierent widths at the overlapping sections, anelement in one of the grooves having an opening therethrough, and aninternally threaded fastening element in the other of said grooveshaving a cylindrical extension thereon extending through the rstmentioned element and securing the two elements together.

3. In an electrical device, the combination comprising a support ofmoldable, electrical insulating material including a wall having anopening therethrough effected by overlapping grooves lying in parallelplanes, entering from opposite edges of the wall and of diii'erentWidths at the overlapping sections, a conducting strip having an openingtherethrough in one of the grooves, a tapped fastening device andterminal screw socket in the other groove having a cylindrical extensionextending through the conducting strip and securing the strip.

4. In an electrical circuit closing and breaking device the combinationcomprising a case of molded electrical insulating material including aWall having an opening therethrough eiected by overlapping sections ofgrooves lying in parallel planes and entering from opposite edges of theWall and of different widths at the overlapping sections, a contactstrip in one of the grooves having an opening therethrough, a tapped nutin the other groove having a tapped, axial, cylindrical extensionextending through the opening in the contact strip and rolled over tosecure the contact strip thereto, and a terminal screw in the nut.

5. In a device of moldable material, the combi nation comprising a Wallhaving an opening therethrough intermediate the edges thereof effectedby grooves entering from different points at the edges of the Wall andhaving sections overlapping transversely of the plane of the wallforming the opening through the Wall, an element in one of the groovesengaging the side edges thereof, and another element in the other grooveengaging a wall of the groove and secured to the rst mentioned element.

6. In a device of moldable material, the combination comprising a Wallhaving an opening therethrough effected by grooves in opposite sidefaces of the Wall, entering from different points at the edges of theWall and having sections overlapping transversely of the plane of theWall forming the opening through the Wall, an element in one of thegrooves at the overlapping section, and a fastener in the other of saidgrooves securing the iirst mentioned element in position in the groove.

'7. In a device of moldable material, the combination comprising a Wallhaving an opening therethrough effected by grooves of different widthsin opposite side faces of the Wall, entering from opposite edges of theWall and having sections intermediate the edges of the Wall overlappingtransversely of the plane of the Wall, an element in one of the groovesat the overlapping section, and a fastening element in the other of saidgrooves securing the rst mentioned element in position in the groove.

ALBERT B. RYPINSKI.

